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Each relay can be operated through more than one setpoint. In this case, relay is
operated using an OR scheme, i.e., the relay is activated when at least one of the
setpoints handling the relay is operated, and the relay is released if there is no one of
the setpoints operated.
Pulse Output Relay
Each relay can be configured to output energy pulses, or to indicate by a pulse the
beginning of a demand or tariff interval (see above). The pulse width is about 100-
200 ms.
NOTE
A relay output may not be shared by independent applications, so allocating the same
relay for pulsing and setpoint operation is impossible. An attempt to reallocate any relay
allocated for pulsing will have no effect. Reallocating a relay previously allocated for a
setpoint, to output pulses will be admitted. In this case, the setpoint holding the same relay
output will be automatically suppressed.
4.10 Analog Output Operation
Analog Output Options
The PM295 has one free-scalable current output 0-20/4-20 mA (upon order) that
provides transmitting a current proportional to the measured quantity through
external load (current loop). The analog output is galvanically isolated and provided
with internal power source +24 V. The current loop resistance can be in the range of
200-500 Ω.
The analog output has two modes of operation: non-multiplexed and multiplexed. In
non-multiplexed mode, the analog output is permanently assigned to a single
parameter. In multiplexed mode, the PM295 provides time-sharing of the analog
output for up to 16 parameters.
Multiplexed Analog Output
The analog output multiplexer is controlled by one to four status inputs, which must
be allocated by the user as selectors for analog output if he wants to use it
multiplexed. The binary combination representing the output parameter number
(output channel) should be provided by the user on status inputs to select the output
parameter.
Using a single status input, the user can obtain two multiplexed channels, with two
status inputs - up to 4, with three status inputs - up to 8, and with four status inputs
72
Operation Techniques
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